// Boost.Units - A C++ library for zero-overhead dimensional analysis and // unit/quantity manipulation and conversion // // Copyright (C) 2003-2008 Matthias Christian Schabel // Copyright (C) 2008 Steven Watanabe // // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) /** \file tutorial.cpp \brief Basic tutorial using SI units. \details Tutorial Defines a function that computes the work, in joules, done by exerting a force in newtons over a specified distance in meters and outputs the result to std::cout. Also code for computing the complex impedance using std::complex<double> as the value type. Output: @verbatim //[tutorial_output F = 2 N dx = 2 m E = 4 J V = (12.5,0) V I = (3,4) A Z = (1.5,-2) Ohm I*Z = (12.5,0) V I*Z == V? true //] @endverbatim */ //[tutorial_code #include <complex> #include <iostream> #include <boost/typeof/std/complex.hpp> #include <boost/units/systems/si/energy.hpp> #include <boost/units/systems/si/force.hpp> #include <boost/units/systems/si/length.hpp> #include <boost/units/systems/si/electric_potential.hpp> #include <boost/units/systems/si/current.hpp> #include <boost/units/systems/si/resistance.hpp> #include <boost/units/systems/si/io.hpp> using namespace boost::units; using namespace boost::units::si; quantity<energy> work(const quantity<force>& F, const quantity<length>& dx) { return F * dx; // Defines the relation: work = force * distance. } int main() { /// Test calculation of work. quantity<force> F(2.0 * newton); // Define a quantity of force. quantity<length> dx(2.0 * meter); // and a distance, quantity<energy> E(work(F,dx)); // and calculate the work done. std::cout << "F = " << F << std::endl << "dx = " << dx << std::endl << "E = " << E << std::endl << std::endl; /// Test and check complex quantities. typedef std::complex<double> complex_type; // double real and imaginary parts. // Define some complex electrical quantities. quantity<electric_potential, complex_type> v = complex_type(12.5, 0.0) * volts; quantity<current, complex_type> i = complex_type(3.0, 4.0) * amperes; quantity<resistance, complex_type> z = complex_type(1.5, -2.0) * ohms; std::cout << "V = " << v << std::endl << "I = " << i << std::endl << "Z = " << z << std::endl // Calculate from Ohm's law voltage = current * resistance. << "I * Z = " << i * z << std::endl // Check defined V is equal to calculated. << "I * Z == V? " << std::boolalpha << (i * z == v) << std::endl << std::endl; return 0; } //]